Label-free electrochemical biosensor for ultra-low level detection of Ag(I) using ssDNA functionalized multi-walled carbon nanotube

Prolonged exposure to silver(I) could harm both human health and the environment. This paper proposes the fabrication of a sensitive, selective, and facile electrochemical biosensor based on non-covalent ssDNA-MWNT hybridization to detect the Ag+ ions in an aqueous medium. Exploration by cyclic voltammetry revealed selective detection of Ag+ metal ions by exploiting Cytosine-Cytosine mismatch chemistry to form specific Cytosine-Ag(I)Cytosine complexes. The biosensor recorded the lowest 1 pM silver ion concentration in the aqueous medium, and real sample studies further proved its potential for trace amount determination in the aqueous medium for environmental monitoring purposes.

Automated summary

This paper proposes a sensitive, selective, and facile electrochemical biosensor based on non-covalent ssDNA-MWNT hybridization for the detection of Ag+ ions in an aqueous medium. The biosensor achieved selective detection of Ag+ metal ions with a lowest concentration of 1 pM in the aqueous medium, and showed potential for trace amount determination in real sample studies for environmental monitoring purposes.